Mince the onion into 0.2 inch chunks.*1
Use a small microwave safe bowl and add the minced onion. Wrap it and microwave for 90 seconds. Then, open the wrap and cool it down completely.
After the onion is cooled down, In a medium bowl, add ground pork, ground beef and salt. Then, kneel until you get a little stickiness.
In the bowl, add microwaved onion, large egg(s), water, panko, black pepper, nutmeg, Worcestershire sauce, and bouillon. Then mix well but do not kneed too much.
After mixed, grab some of the mixture and toss a couple times to remove some air.
Divide the mixture into 4. *2
This mixture is loose but make a circle shape and while making circle, toss in order to release air inside the ball.
Dip the patties into flour first and dust with extra flour.
Prepare a medium bowl, and add egg(s). Mix well. Then dip in the egg mixture bowl and brush off any excess.
Then, cover them in Japanese panko.
Heat the oil to 320-340°F (160-170°c). When the oil hits this point, gently put two in. Cook two at a time otherwise the oil's heat drops dramatically. Fry for 4 minutes each side.
Move to a wire rack to drain excess oil. (Or paper towel)